I'm new to the forums. Although I have a basic, limited understanding of biology, I'm interested in the concept of creating or altering organisms on a molecular level. I have a few hypothetical questions about this topic that I hope someone can answer.

First of all, I'd like to say that I understand these are broad, very theoretical (perhaps even silly) questions, and also that harmful organisms come in great variety. So even if you want to concentrate on the organism which you think is best applicable here, that would be fine. I understand as well that research on such things as I propose here may be slim or unreliable, but I'm only looking for 'possibility' here, not practicability or current, solid proof.

So here are the questions.

1. Is it theoretically possible, to actually 'create' a virus, bacteria, prion or other contagious, harmful organism, or only theoretically possible to alter the genetic make up of an already existing one? Whether it is possible or not, could you give me a short layman's definition of how creation or alteration would work, and a theoretical, again, layman's, explanation of its limitations in the context of;

a) the effects of an organism,ie how far from its 'normal' symptoms in humans can it be altered? eg could the rabies virus be altered to cause some of the symptoms of something entirely different?b) which organisms (prions, bacteria, viruses) are most easily altered?

2. a) Concerning prions, viruses, and bacterium's effects on human anatomy; is it possible for an organism of any kind to have a suppressant effect on emotions or personality? For instance, could an organism theoretically cause people to behave in a particular way; placid, undesirous, or indeed even to act compassionately? Or on the other hand, completely primal, unhinged and psychotic?

b) if these are possible, could you give me a layman's explanation of how that might work inside the brain?

3. Is it possible for a harmful organism to be altered to withstand extremely high temperatures, thousands of degrees even?

4. And finally, could you give me a brief, basic explanation of how natural immunity to viruses, bacteria, or prions works?

I want to point out, in regard to my last question, I understand the basic idea of t and b cells, y protiens and phagocytes but I'm not talking about acquired immunity, I'm talking about this;

If a person contracts a virus that is harmful to others around them, yet they suffer no effects, perhaps due to a genetic abnormality. A virus, for instance, like ebola; where it is infectious and dangerous to anyone who comes into contact with it. Is if possible for some form of abnormality or some other biological quirk to make someone completely immune to such a contagion?

Your post reads like you want an idea to create a superbug. Is it possible - yes. What you need is a mad scientist. You asked if it's possible to create an artificial bacterium or virus - the answer is yes. However, why would anyone want to re-invent the wheel? As far as affecting personality, how about a virus that would introduce a set of genes required for ethanol synthesis directly into a host? In terms of natural immunity, the mechanism is the same one that prevents most viruses from causing disease in unrelated organisms - differences in cell membranes and/or cellular metabolism.

Ethanol synthesis, that would work in some way, but the behavior that is caused by that would be obviously subjective to the host - not everyone behaves the same drunk. What I'm talking about is something that would change brain function to emit a pre-determined emotional and cognitive response, a universal behaviour-changing mechanism, similar to the way that rabies, in its latter stages, causes anger, confusion and aggression. I don't want to create a superbug, no lol except in theory.

One example that comes to mind, that already exists, is toxoplasma gondii, which interestingly, can cause a cerebral infection which has been found to change sexual behavior in women - making them more promiscuous. It's theorized that this is because the virus wants to spread to a new host. 'A kind of 'viral personality' -a virus creating changes in a host's behavior to further its own existence.

Ideally, this theoretical organism of mine would be able to be manipulated further than this, to effect higher brain function, to create profound changes in brain chemistry that make for specific behavioral responses.